Lampriformes - Description and Ecology

Description and Ecology

These oceanic fishes are pelagic feeders that stay well above the seafloor, and normally occur in waters 100–1000 meters deep. They are typically brightly coloured as adults, often with brilliant crimson fins. Lampriforms have a highly variable body form, but they are generally laterallly compressed. Some are rounded in lateral view, while others are very elongate. The former are termed bathysomes – "deep-bodies", from Ancient Greek bathýs (βᾶθύς) "deep" + sōma (σῶμα) "body" – and the latter taeniosomes – "ribbon-bodies", Greek tainía (ταινία) "ribbon". They vary greatly in size, too, ranging from less than 30 cm (12 in) in the sailfin moonfishes (Veliferidae) to Regalecus glesne, the longest of all living bony fishes, which may reach 17 m (56 ft) in length.

The lampriforms have 84-96 total vertebrae; an orbitosphenoid bone is present in some members of this order. Their premaxilla completely excludes the maxilla from the gape, but the jaws are highly protrusible nonetheless. The upper jaw's protrusion is achieved in a unique way: the maxilla, instead of being ligamentously attached to the ethmoid and palatine, slides in and out with the highly protractile premaxilla. The pelvic fins have up to 17 rays and are placed rather far toward the front of the animal, but they can be missing entirely. The dorsal fin is long, and tend to extend along most of the length of the body. Fin spines are absent in all. Some have a physoclistous gas bladder, while others have none. They either have tiny scales or naked skin.